Breakdown Behavior of AlGaN MSM UV Photodetectors
- PDF / 338,191 Bytes
- 5 Pages / 414.72 x 648 pts Page_size
- 78 Downloads / 221 Views
spacing (d) vary from 21.m to 16jtm. The total interdigital area is 1.0mm 2 . The AlGaN surface was cleaned using standard ultrasonic solvent cleaning process followed by dipping in HCI:H 20 (1:1) solution for 30 sec. Image reversal photolithography, Ebeam metallization and lift-off techniques were used for generation of the interdigital electrode pattern. Oxygen plasma was used for the surface treatment after lift-off process. Annealing process for the contact of Au/Ti/A1GaN was conducted at 500'C in the N 2 ambient for 10 min. Comparison studies have been performed on the MSM photodetectors before and after the annealing process. Shown in Figure 2 is the schematic of the measurement system setup for optical and I-V characteristics measurements. 75Watt Xe lamp was used as UV light sources. The probe •• \ station was equipped with a PCI TTser heater and a thermocouple for PPob oncroae XeLight
testing at elevated temperatures Newport 1830-C Optical e toAmplifier w sePower Mpo eter~= Meter was employed to
calibrate the light beam intensity. I-V characteristics was measured using Tektronics Semiconductor Work Bench 372 (noise level - 1 pA).
I-vTester oMorocromter current Temperaturecontroller oscilloscop . ope O
ei Xe0Pulse
ca
am
am
Figure2:
Measurement system setup
III. RESULTS AND DISCUSSIONS The I-V characteristics of an Au/Ti/A1GaN MSM PD with an
10
-
electrode line width of 16jtm and an electrode spacing of 12pm, before and after annealing process (shown in Figure 3). The Schottky barrier height was reduced after annealing. The junction becomes more "ohmic-like"
Unannealed
......-Annealed at 500C 8
"
/
.r4
o
1, 6 00 .. 04
0.00
(see insert). The current at low bias (V
Data Loading...
